Johan Georg Røebye Grüner (26 October 1817 – 16 November 1890) was a Danish landowner, politician and co-founder of Landmandsbanken.
[2] Grüner matriculated from Sirø Academy in 1836 and acquired the Candidate of Law degree from the University of Copenhagen in 1842.
Together with Counts C. E. Frijs of Frijsenborg, J. Frijs of Juellinge and baron Otto Rosenørn-Lehn, he bought the Tersløsegård main building and garden in 1861, where the four Soranians established the Holberg Downer House (Holbergs Enkesæde).
In 1849 he established a local savings bank, In 1871 he was one of the founders of the Landmandsbanken (chairman of the bank council 1871–72 and again in -84) and in 1872 took the initiative to establish the United Municipalities' Old Age Pension Fund (De forenede kommuners alderdomsforsørgelseskasse), whose president he was until his death.
She was the daughter of civil servant in the Ministry for the Interior Carl Gisle Gunnar Simonsen (1813–84) and Ida Sofie Adamine Clara Rosalie Krogh-Kierulff (1824–1909).